The present invention relates to an apparatus for continuous dehydration of a cloth with the use of a closed chamber under increased or reduced pressure comprising a space formed with four rolls as its main constituents.
As an example of the apparatus for continuously dehydrating a cloth soaked with a treating solution and running continuously, a squeeze mangle comprising a pair of pressure rolls pressed with each other has been well known. However, since such a liquid squeeze means comprising merely the combination of pressure rolls has a limit in its pressing force to be applied for the cloth, a sufficient liquid squeezing cannot be done frequently. For instance, a squeeze mangle comprising the combination of two pressure rolls can only squeeze the cloth up to about 50%, so that a sufficient dehydration cannot be expected. To elevate the squeeze effect, it has also been proposed to combine four rolls (a) pressed with one another as shown in FIG. 1, in which the space (b) surrounded with the four rolls is made into a reduced pressure chamber to squeeze the cloth due to the effect of the contact pressure of the rolls and the reduced pressure in the space (b). However, in such a squeeze apparatus, a cloth to be transported continuously must be bent along a roll (a), not going straight, so that there occurs a problem that creases are caused to occur to the cloth in guiding the cloth in a bending way. To avoid the occurrence of creases by transporting the cloth straight, it has also been proposed, as shown in FIG. 2, to provide intermediate rolls (d), (d) respectively between the squeeze rolls (a), (a) and (a'), (a') and to make the space (b') surrounded with the squeeze rolls and the intermediate rolls as a reduced pressure chamber for squeezing the cloth passing through this reduced pressure chamber. In this apparatus, however, particularly when the lengths of the rolls (a), (a') and (d) are long in accordance with the width of the cloth, the rolls, particularly the intermediate rolls (d) are bent unavoidably to the direction of the reduced pressure chamber due to the effect of negative pressure, so that there occurs gaps between the squeeze rolls and the intermediate rolls to cause such a trouble that the interior of the reduced pressure chamber cannot be maintained in a state of negative pressure effectively.